Apart from well known stuff like start_form_tag being deprecated, these things broke for us with Rails 2.0.2:1. Super is no longer called in tests. Use setup_with_fixtures instead, which will work in rails 2.0.2 and future versions where the bug is fixed.2. The paths to partials used by ActionMailer have changed – now we must use “controllername/partialname” as opposed to “../controllername/partialname”3. The handling of plusses in urls has changed. It probably changed in this changeset. The result is that passing a + in a url path no longer gets translated to a space in the handling done by rails. So now we have correct handling according to RFC2396.